1. Field of the Invention
The present invention relates to a display system, which is called "a head mount display", which is put on a human head for displaying an image in front of his eyes.
2. Description of the Related Art
There has been known a display system using a small liquid-crystal panel, which is called "a head mount display (HMD)" (for example, refer to an article disclosed in the October issue of a "Monthly LCD Intelligence" published from Kabushiki Kaisha Press Journal in October 1996, pp. 59 to 64).
The display system as disclosed there is designed such that an image is displayed at a location apart forward from eyes by about several centimeters to recognize a virtual realistic image. Such a display system is applicable to something to play such as a TV game, movie seeing, education, presentation or medical treatment.
As a method of displaying an image using the HMD, there is a 3D (three-dimensional image) technique. In this case, a horizontal angle of visibility ranging from 60 to 90.degree. is required.
However, the head mount display suffers from such a problem that the effective area (a visual area) of pixels is caused to change according to an angle of view since a distance between the liquid-crystal panel and eyes is short to the degree of about several centimeters.
The above problem causes that the visual feeling of the image is different or an unfamiliar feeling occurs depending on the horizontal angle of view.
In the general liquid-crystal display, since a distance between eyes and a screen is far to the degree of several ten centimeters or longer, the above-mentioned difference in the effective area of pixels according to a difference of the horizontal angle of view does not cause any problems.